鲶鱼的保护、生态和管理:第二国际研讨会

寻找平衡:人口参数和变量招聘介绍蓝鲶人群在四维吉尼亚潮汐河流系统

罗伯特·s . Greenlee和凯瑟琳n Lim

doi:https://doi.org/10.47886/9781934874257.ch30

文摘引进了蓝鲶Ictalurus furcatus大西洋人口潮汐河流的斜率支持重要的休闲和商业渔业,詹姆士河奖杯渔业是全国公认的。BOB国际体育2001 - 2008年期间,低频(15脉冲/秒)脉冲直流electrofishing用于样本在潮汐fresh-oligohaline部分蓝鲶的詹姆斯,Mattaponi, Pamunkey,和接受的河流系统;54174蓝鲶收集,和4660岁的这些都是使用耳石。通常意味着单位努力赶上(CPUE)高(从223年到6106年每小时鱼)。提高CPUE趋势随着时间发生在詹姆斯(839 - 4449每小时鱼)和接受每小时鱼(1400 - 6106)河流、河流和CPUE的差异被发现。时间增长)岁(平均长度的变化被观察到,与所有年龄的增长放缓Pamunkey河和减缓老年年龄的Mattaponi第四(年龄)和接受(8 - 12岁和14岁)河流。Pamunkey和接受河流、经济增长之间存在着负相关关系(平均长度10岁)和密度(CPUE)。虽然在詹姆士河密度急剧增加,增长保持稳定。河流之间的增长变化;研究结束时,意味着总长度10岁的416毫米不等接受詹姆士河河675毫米。 Growth through age 15 fi t linear models, as opposed to the von Bertalanffy nonlinear curve. In three of the four populations, the maximum age sampled increased in each succeeding survey year, and the maturing of all four populations was reflected in concurrent increases in size distributions. Recruitment was variable, with coincident strong and weak year-classes occurring in all four populations—an implication that landscape-level environmental variables play a role in determining recruitment success. In three of the four populations, patterns in year-class strength persisted, with correlation of catch-curve residuals from surveys separated by time. Approximately 35 years poststocking in the James and Rappahannock rivers and 25 years poststocking in the Mattaponi River, these populations had not yet reached equilibrium. It is unknown what the dynamics of blue catfish abundance, growth, and survival will be in the long-term in these rivers, leaving uncertainty regarding the future of the fisheries the populations support, as well as unanswered questions related to potential effects on other species.